Chapter 6: Sedimentry and Metamorphic rocks Flashcards
sediments
pieces of solid material that have been deposited on the earths surface by water, wind, ice, gravity or chemical precipitation
clastic sediments
have worn down edges and rounded corners from physical abrasion comes from the word klastos meaning broken
lithification
the physical and chemical processes that transform sediments into sedimentry rock
cementation
when mineral growth cements sediment due grains into solid rock
Bedding
horizontal layering of rocks
graded bedding
where the partical sizes become increasingly heavier and coarser towards the bottom
cross bedding
inclined layers of sediment move forward across a horizontal surface
why do sediment deposits tend to form in layers
due to partical size and timing
coarse grained clastic rock
conglomerate and breccia
medium grained clastic rock
sandstone
fine grained clastic rock
shale
organic sedimentry rocks
limestone and coal
what are evaporites
When the concentration of dissolved minerals in a body of water reaches saturation, crystal grains precipitate out of the solution and settle on the bottom. The layer of chemical sedimentry rocks that form on the bottom are evaporites
What does metamorphism mean
change
regional metamorphism
when temperature and pressure affect large portions of the Earth’s crust
contact metamorphism
When molten rocks such as those in an igneous intrusion come in contact with solid rock
hydrothermal metamorphism
When very hot water reacts with rock and alters its chemistry and mineralology
foliated vs. nonfoliated
wavy layers and bands of minerals vs. lacking mineral grains with long axes in one direction
porphyroblasts
metamorhpic minerals that grow quite large while the surrounding minerals remain small
